Progressive ophthalmic lenses are known to include far vision, near vision and passage areas. The far vision area and the near vision area have different powers and this causes the lens to contain optical aberrations that are typically distributed in the lateral areas on both sides of the power progression passage, which are inevitable and inherent to the fact that various differentiated optical powers exist. These optical aberrations, which are not desirable but inevitable, can, in a non-limiting way, be field curvature, oblique astigmatism, coma, etc. Various techniques exist for reducing and distributing these aberrations along the surface of the lens so that they affect the user as little as possible. In addition, it is possible that the user requires astigmatism correction. This astigmatic correction can also be included in the lens by so-called prescription astigmatism. Logically in the physical lens prescription astigmatism and said optical aberrations coexist in an overlapped state, but during the procedure for designing the lens these characteristics are treated in a differentiated way.
Thanks to existing optical aberration optimization techniques, preferably referring to the distribution of the lens power progression associated aberrations, such as oblique astigmatism, coma and field curvature, among others, greater comfort has been achieved for progressive lens users and, consequently, said lenses have become popular. In this application, the term “lateral aberrations” will apply to all those optical aberrations that are the result of progressive lens power progression, including, among others, oblique astigmatism, coma and field curvature.
It is known to take into account various physiological data, such as the frame chosen by the user, in the procedure of selecting the most suitable progressive lens for the user. For example, in certain cases, data are taken on the positioning of the lens with respect to the user's eye, taking into account the selected frame. Examples of this can be found in documents ES 2.253.391 and WO 2009/133887 A1.
Document EP 1.830.222 A1, EP 1.950.601 A1, JP 2004163787 A, and WO 2009/135058 A2 describe different procedures for manufacturing progressive lenses that take into account the frame chosen by the user.
However there is still the need to devise procedures that improve the treatment of optical aberrations present on lenses, and very particularly distributing power progression associated lateral aberrations.
In this application, the terminology of the ISO 13666 standard has been used, which establishes the following definitions:                semifinished lens blank: piece of preshaped material that only has one finished optical surface,        finished lens: lens where the two sides have finished optical surfaces, this finished lens can be bevelled (to adjust its perimeter to a particular frame) or not.        
In this application, it is considered that the expression “finished lens” always relates to the unbevelled lens. For the bevelled lens the term “bevelled finished lens” is specifically used.